View source for 1xxu


==Crystal Structure of AhpE from Mycrobacterium tuberculosis, a 1-Cys peroxiredoxin==
<StructureSection load='1xxu' size='340' side='right'caption='[[1xxu]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xxu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XXU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XXU FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1xxu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xxu OCA], [https://pdbe.org/1xxu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xxu RCSB], [https://www.ebi.ac.uk/pdbsum/1xxu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xxu ProSAT], [https://www.topsan.org/Proteins/TBSGC/1xxu TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AHPE_MYCTU AHPE_MYCTU] Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides. May represent an important antioxidant defense against cytotoxic peroxides, especially peroxynitrite, which can be formed by activated macrophages during infection.<ref>PMID:19737009</ref> <ref>PMID:24379404</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/xx/1xxu_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1xxu ConSurf].
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== Publication Abstract from PubMed ==
All living systems require protection against the damaging effects of reactive oxygen species. The genome of Mycobacterium tuberculosis, the cause of TB, encodes a number of peroxidases that are thought to be active against organic and inorganic peroxides, and are likely to play a key role in the ability of this organism to survive within the phagosomes of macrophages. The open reading frame Rv2238c in M.tuberculosis encodes a 153-residue protein AhpE, which is a peroxidase of the 1-Cys peroxiredoxin (Prx) family. The crystal structure of AhpE, determined at 1.87 A resolution (R(cryst)=0.179, R(free)=0.210), reveals a compact single-domain protein with a thioredoxin fold. AhpE forms both dimers and octamers; a tightly-associated dimer and a ring-like octamer, generated by crystallographic 4-fold symmetry. In this native structure, the active site Cys45 is in its oxidized, sulfenic acid (S-O-H) state. A second crystal form of AhpE, obtained after soaking in sodium bromide and refined at 1.90 A resolution (R(cryst)=0.242, R(free)=0.286), reveals the reduced structure. In this structure, a conformational change in an external loop, in two of the four molecules in the asymmetric unit, allows Arg116 to stabilise the Cys45 thiolate ion, and concomitantly closes a surface channel. This channel is identified as the likely binding site for a physiological reductant, and the conformational change is inferred to be important for the reaction cycle of AhpE.

Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin.,Li S, Peterson NA, Kim MY, Kim CY, Hung LW, Yu M, Lekin T, Segelke BW, Lott JS, Baker EN J Mol Biol. 2005 Mar 4;346(4):1035-46. Epub 2005 Jan 25. PMID:15701515<ref>PMID:15701515</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Baker EN]]
[[Category: Hung LW]]
[[Category: Kim CY]]
[[Category: Kim MY]]
[[Category: Lekin T]]
[[Category: Li S]]
[[Category: Lott JS]]
[[Category: Peterson NA]]
[[Category: Segelke BW]]
[[Category: Yu M]]